The present invention relates generally to a method for preparing pinacols from organic carbonyl compounds electrochemically. More particularly it relates to an improved process for electrochemically producing pinacols in a cell having a hydraulically impermeable cation-exchange membrane, an acid medium, and careful concentration control of the materials charged to the cell.
Pinacols are intermediates which are useful in the preparation of polymers, pharmaceutical products and pesticides but have been avoided as a synthesis route to these products because only unsatisfactory methods of manufacturing the pinacols are available today. Electrolytic reduction or couping of acetone to form pinacol, (2,3-dimethyl-2,3-butanediol), has been carried out on an experimental basis for a number of years to produce small quantities of pinacol. Such processes though have thus far failed to receive much commercial utilization because of the cost factors involved in these methods which employ quantenary ammonium salts and porous separators, resulting in low current efficiencies.